By default, Team Explorer always tries to automatically connect at startup to the latest known Team Foundation Server. In my case I often start Visual Studio Team System at home when I was previously connected to the Team Foundation Server at work. So, when disconnected from work, I always get the TF30331 error …

To make this happen, add a DWORD value called “AutoLoadServer” under HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\8.0\TeamFoundation (for 2005 – change this to 9.0 for Orcas). A setting of Zero means do not reconnect automatically.